Pumping apparatus



June 2, 1964 A. A. HAYS ETAL 3,135,219

PUMPING APPARATUS Filed Sept. 29, 1960 Fig. 1

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2.9 F INVENTOR.

Archie A. Hays BY Ruff/n R Davis 3 1 yfivf/w ATTORNEY tenance.

United States Patent 3,135,219 PUMPING APPARATUS Archie A. Hays,Dickinson, and Rufiin .1. Davis, League City, Tern, assignors, by mesneassignments, toStandard Gil Company, Chicago, TIL, a corporation ofIndiana Filed Sept. '29, 1960, Ser. No. 59,353 2 Claims. (Cl. 103-153)This invention relates to reciprocating type pumps and a check valveassembly used therewith. More particularly, this invention relates tosuch a pump for handling relatively small quantities of liquid at highpressures.

In many petroleum and chemical processing plants it is often desirableto pump small quantities of liquid, i.e. about to 150 ml. of liquid perhour, into high pressure systems, i.e. as high as about 3,000 p.s.i.g.Many available pumps are not capable of being operated effectively andeconomically under these conditions.

An object of the present invention is a pump adapted to pump smallquantities of liquid against high pressures. Another object of thepresent invention is a small volume pump which may be operatedefliciently and economically. A further object of this invention is apump which is easy to maintain and which requires a minimum of main-Further objects will become apparent from a reading of the followingdescription of the pump of the present invention.

The present invention provides a pump cylinder, a reciprocating plungerwithin said cylinder having an intake stroke and a discharge stroke, anda particular check assembly mounted on the cylinder. The check valveassembly includes an inlet conduit, an outlet conduit, and a valvechamber in flow communication with the inlet and the outlet. A floatingcheck member is positioned within the valve chamber which is in flowcommunication with the pump cylinder. A seating surface is provided inthe inlet which is adapted to receive the check mem ber in sealingcontact therewith during the discharge stroke of said plunger. .Acheck-retaining washer member is positioned at the end of the valvechamber adjacent the pump cylinder, the washer member being providedwith an opening therein so that the check member is retained in thevalve chamber, while permitting the fluid to be pumped to pass throughthe opening into the pump cylinder during the intake stroke of theplunger. A discharge check valve is provided in the outlet conduit toseal oif the valve chamber during the intake stroke of the plunger andprevent the return of fluid discharged from the pump into the externalsystem.

A better understanding of our invention will be had from the followingdescription of a preferred embodiment of the invention and from theaccompanying drawings wherein:

FIGURE 1 is an elevational view of the pump of the present invention,

FIGURE 1a illustrates a preferred pump cylinder employed in the pump,

FIGURE 1b illustrates a preferred plunger employed in the pump,

FIGURE 2 illustrates a preferred embodiment of the check valve assemblyemployed with the pump, and

FIGURE 3 is a preferred check-retaining washer employed in the abovecheck valve assembly.

Referring to FIGURE 1, the pump 11 preferably is mounted on a basemember 12 and is driven by a drive member 13 also mounted on the base.The drive 13 may include an electric motor with a speed reducer and amechanical linkage to a rack and pinion assembly coupled to the pumpplunger 14. Other types of drive mechanisms may be employed, however, toimpart a reciprocating motion to the plunger 14 within the pump cylinder16. Advantageously, the coupling 17 is adjustable and a lock nut isprovided so that the length of the plunger stroke may be adjusted over awide range and set at the desired position.

A check valve assembly 18 is connected to the outboard end of thecylinder 16 by threaded engagement therewith. However, flanges or othersuitable connections may be employed. The check valve assembly 18 isprovided with an inlet line 19 through which is supplied the fluid to bepumped, and a discharge line 21 through which the fluid discharged fromthe pump flows into an external system.

Referring to FIGURE 2, the check valve assembly 18 is screwed onto theoutboard end 15 of the pump cylinder 16. The joint between the valveblock 26 and the cylinder 16 preferably is sealed by an O-ring 27between the outboard end of the cylinder and a shoulder 28 provided inthe valve block 26. The valve block 26 is provided with an inlet conduit29 through the outboard end of the valve block and substantially inalignment with the bore of the cylinder 16. An outlet conduit 31,usually of smaller size than the inlet conduit, is also provided in thevalve block 26 and, preferably, is at a substantially right angle to theinlet conduit 29. The inlet 29 and the outlet 31 are in flowcommunication with a valve chamber 32 within which is positioned a checkmember 33. The check member 33 may be cone shaped or of another shapeparticularly well adapted for use with specific fluids, but preferablyis a ball having a diameter slightly less than the diameter of the valvechamber 32. At the inboard end of the valve chamber 32 there is placed awasher member 34 which acts to retain the check member 33 Within thevalve chamber 32.

During the intake stroke of the plunger 14 the fluid to be pumped passesthrough the inlet 29 into the valve chamber 32 and the floating checkmember 33 is drawn against the retaining washer 34. The washer member34, as shown in FIGURE 3, is provided with a noncircular opening 35,which advantageously is substantially rectangular in shape. The openinghas appropriate dimensions so that the check member 33 will not passthrough the opening into the bore of the cylinder 16, while permitting asmall volume of the incoming fluid to pass around the check and throughthe opening into the bore of the cylinder 16. This arrangement permits avolume of fluid equal to the quantity to be pumped to bleed into thecylinder bore and has been found to considerably reduce shock andpulsation during the operation of the pump.

As the plunger 14 moves in the outboard direction on the dischargestroke, the check member 33 is forced against a seating surface 36provided in the inlet 29 and contacts this seating surface to seal theinlet from the high pressure fluid. An additional check valve may beemployed in the suction conduit upstream of the pump if desired, butthis is not generally required. The fluid being pumped passes from thecylinder bore into the valve chamber, through the outlet 31 and througha check valve member 37 provided in the discharge conduit 31. The checkvalve member 37 permits fluid to be discharged from the pump during thedischarge stroke and seals off the valve chamber 32 from the externalsystem during the intake stroke of the plunger.

Preferably the check-retaining washer 34 is positioned in a recess 38provided adjacent the inboard end of the valve chamber 32 and is held inplace between the outboard end of the cylinder 16 and the shoulder 28.

The materials used in the construction of the various parts of theapparatus as described above may be any suitable material which iscompatible with the fluid to be pumped under the service conditionsemployed. Normally the pump cylinder 16, the plunger 14, and the valveblock 26 will be steel or a corrosion resistant alloy, and

the check member 33 and the washer 34 are made from a material havingthe desired corrosion resistance and hardness. Furthermore, the seatingsurface 36 in the block 26 and the seating surface on the washer 34 maybe provided with a suitable soft seat, such as tetrafluoro-' ethylene orthe like.

A pump such as described above has been tested and operated successfullyover long periods of time, pumping small Volumes of liquid against ahigh pressure with minimum variations in the flow rate. One such pumpwas constructed as shown in FIGURE 2. This pump had a 7 /2" long by /4"diameter AISI 4140 steel plunger operating in an 18-8 chrome-nickelstainless steel cylinder through a Teflon packed packing gland. Thevalve block of 18-8 chrome-nickel stainless steel was provided with a A"IPS inlet, reduced to a diameter bore in the block, and a /8" IPS outletreduced to a A" diameter bore in the block. A 4" diameter ball was usedin the valve chamber which was /2" deep by 0.26 diameter. The washer 34was diameter by thick, provided with a 7 square hole in its center. Aspring loaded ball check valve was employed in the discharge conduit.

The above-described pump handled heavy catalytic cycle oil at aconsistent flow rate of about 37 ml. per hour and was pumped into anexternal system against about 1,000 p.s.i.g. Thus, the pump of thepresent invention has been found to be capable of pumping smallquantities of fluid against high pressures and has overcome thedifficulties encountered with previous apparatus.

While we have described a preferred embodiment of our invention inconsiderable detail, it is understood that alternative details ofconstruction and operation will be apparent from the foregoingdescription to those skilled in the art.

Having described our invention, what We claim is:

1. Fluid pumping apparatus comprising a pump cylinder, a reciprocatingplunger within said cylinder and a valve assembly mounted on theoutboard end of said cylinder, said valve assembly comprising an inletconduit, an outlet conduit, a valve chamber communicating with saidinlet conduit and said outlet conduit, a ball member positioned in saidchamber, said chamber communicating with the outboard end of saidcylinder, a ball-retaining washer member positioned between said balland said cylinder, a first seating surface in said inlet conduit adaptedto receive said ball member in sealing contact therewith during thedischarge stroke of said plunger, said washer member being provided witha non-circular opening therein, said opening being adapted to retainsaid ball member in said chamber while permitting fluid from saidchamber to pass through said opening into said cylinder during theintake stroke of said plunger, and ball check valve means in said outletconduit adapted to seal off said valve chamber from fluid dischargedtherefrom during the intake stroke of said plunger.

2. Apparatus adapted for pumping small quantities of liquid at highpressure which apparatus comprises a pump cylinder, a reciprocatingplunger within said cylinder and a valve assembly threaded on theoutboard end of said cylinder, said valve assembly comprising a blockmember adapted for threaded engagement with the outboard end of saidcylinder, a first conduit at the outboard end of said block being insubstantial alignment with said cylinder, a second conduit in said blockof a smaller size than said first conduit positioned in said block atsubstantially a right angle to said first conduit, a valve chamber insaid block communicating with said first conduit and said secondconduit, a ball member positioned in said chamber, said chambercommunicating with said cylinder, at ball-retaining Washer memberpositioned in a recess provided in said block adjacent the end of saidchamber communicating with said cylinder, a first seating surface insaid first conduit adapted to receive said ball member in sealingcontact therewith during the discharge stroke of said plunger, saidwasher member being provided with a rectangular opening therein, saidopening being adapted to retain said ball member in said chamber whilepermitting fluid from said chamber to pass around said ball through saidopening into said cylinder during the intake stroke of said plunger,O-ring sealing means positioned between the outboard end of saidcylinder and a shoulder provided in said block adjacent said washermeans and spring loaded ball check valve means in said second conduitadapted to seal oif said valve chamber from fluid discharged therefromduring the intake stroke of said plunger.

References Cited in the file of this patent UNITED STATES PATENTS999,608 Stucky Aug. 1, 1911 1,384,097 Schlachs July 12, 1921 1,555,718Schroeder Sept. 29, 1925 1,715,901 countryman June 4, 1929 1,764,186Teesdale June 17, 1930 1,901,217 Yerkes Mar. 14, 1933 2,026,058 PerryDec. 31, 1935 2,789,510 Meynig Apr. 23, 1951 2,843,045 Mashinter July15, 1958

1. FLUID PUMPING APPARATUS COMPRISING A PUMP CYLINDER, A RECIPROCATINGPLUNGER WITHIN SAID CYLINDER AND A VALVE ASSEMBLY MOUNTED ON THEOUTBOARD END OF SAID CYLINDER, SAID VALVE ASSEMBLY COMPRISING AN INLETCONDUIT, AN OUTLET CONDUIT, A VALVE CHAMBER COMMUNICATING WITH SAIDINLET CONDUIT AND SAID OUTLET CONDUIT, A BALL MEMBER POSITIONED IN SAIDCHAMBER, SAID CHAMBER COMMUNICATING WITH THE OUTBOARD END OF SAIDCYLINDER, A BALL-RETAINING WASHER MEMBER POSITIONED BETWEEN SAID BALLAND SAID CYLINDER, A FIRST SEATING SURFACE IN SAID INLET CONDUIT ADAPTEDTO RECEIVE SAID BALL MEMBER IN SEALING CONTACT THEREWITH DURING THEDISCHARGE STROKE OF SAID PLUNGER, SAID WASHER MEMBER BEING PROVIDED WITHA NON-CIRCULAR OPENING THEREIN, SAID OPENING BEING ADAPTED TO RETAINSAID BALL MEMBER IN SAID CHAMBER WHILE PERMITTINGK FLUID FROM SAIDCHAMBER TO PASS THROUGH SAID OPENING INTO SAID CYLINDER DURING THEINTAKE STROKE OF SAID PLUNGER, AND BALL CHECK VALVE MEANS IN SAID OUTLETCONDUIT ADAPTED TO SEAL OFF SAID VALVE CHAMBER FROM FLUID DISCHARGEDTHEREFROM DURING THE INTAKE STROKE OF SAID PLUNGER.